I've been brewing for about 5 years now. Started with a coopers kit. Before I knew it it was an obsession.
Then I moved onto extract. Then All-grain. Then I got sick of bottling so I started kegging....
Some good tips here already, I would say to improve your beers go in the following order:
1) Temperature control. As pointed out by FreddoFrog, this will make the biggest difference to your beer. Ale's should be brewed between 18 & 20C. A fridge + temperature controller is the ducks nuts, but you can also get away with putting your fermenter in the laundry sink filled with water, and using frozen PET bottles of water to cool the body of water down around it, then exchange the bottles with frozen ones twice daily as needed.
2) Use a better yeast. Yeast should be fresh, stored cool and of good quality. That yeast that has been sitting under the lid of the tin has been there for god knows how long in what sort of conditions. Try Safale US-05 from any decent homebrew shop.
3) Dont use sugar with your tin of goop. Try a kilo of light dry malt extract and a few hundred grams of dextrose.
4) If you like hoppy beers, buy a packet of hops and add them in. Throw in 15 - 20 grams initially and another 15 - 20 grams in on day 6 will make a world of difference to freshen up your kit. Bottle after at least 10 days.
5) to santize your equipment, the best and cheapest way is to use napisan (find one that has 25% sodium percarbonate). Make up a fairly strong solution in warm water and soak everything in the fermenter overnight. It will come up clean as a whistle, then just simply rinse out and you're good to go.
once you've mastered the above, you will go from brewing OK beer to what your mates will say "Wow, you brewed this?". Then you can start to think about steeping speciality grains, doing a mini boil, etc.
Finally; Have a look at / register on www.aussiehomebrewer.com.au - it's the seabreeze of the brewing world, and there's a huge wealth of info there.
Good luck!
